Listening on 5000 and 5001 - why?

[surfmuggle]

I downloaded the zip file and unzipped it to c:\Dev\GiraffeLunch

c:\Dev\GiraffeLunch>dir
      Directory of c:\Dev\GiraffeLunch

    30/07/2018  15:07    <DIR>          .
    30/07/2018  15:07    <DIR>          ..
    30/07/2018  15:06             1,819 giraffesample.sln
    30/07/2018  15:06             1,071 LICENSE.md
    30/07/2018  15:06    <DIR>          LunchAPI
    30/07/2018  15:06             1,023 README.md
                   3 File(s)          3,913 bytes
                   3 Dir(s)  348,205,043,712 bytes free

I started Visual Studio Code c:\Dev\GiraffeLunch>code . then i changed the fsproj file to remove the watcher reference and bumped most libraries to version 2.1

c:\Dev\GiraffeLunch>dotnet restore
C:\Program     Files\dotnet\sdk\2.1.300\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.ObsoleteReferences.targets(33,5):     warning : The tool 'Microsoft.DotNet.Watcher.Tools' is now included in the .NET Core SDK. Information     on resolving this warning is available at (https://aka.ms/dotnetclitools-in-box).     [c:\Dev\GiraffeLunch\LunchAPI\LunchApi.fsproj]
  Restore completed in 91.35 ms for c:\Dev\GiraffeLunch\LunchAPI\LunchApi.fsproj.

The i started it

c:\Dev\GiraffeLunch>dotnet run --project LunchAPI/LunchApi.fsproj
Hosting environment: Production
Content root path: c:\Dev\GiraffeLunch\LunchAPI
Now listening on: http://localhost:5000
Now listening on: https://localhost:5001
Application started. Press Ctrl+C to shut down.

I wondered why the application is listening on 5000 and 5001?

After a few searches it seems that this is from the kestrel default configuration:

.UseKestrel(options =>
{
    // ....
    options.Listen(IPAddress.Loopback, 5000);
    options.Listen(IPAddress.Loopback, 5001, listenOptions =>
    {
        listenOptions.UseHttps("testCert.pfx", "testPassword");
    });
});